DNA Dynamics under Periodic Force Effects

The sensitivity of DNA to electromagnetic radiation in different ranges differs depending on various factors. The aim of this study was to examine the molecular dynamics of DNA under the influence of external periodic influences with different frequencies. In the present paper, within the framework of a mechanical model without simplifications, we investigated the effect of various frequencies of external periodic action in the range from 1011 s−1 to 108 s−1 on the dynamics of a DNA molecule. It was shown that under the influence of an external periodic force, a DNA molecule can perform oscillatory movements with a specific frequency characteristic of this molecule, which differs from the frequency of the external influence ω. It was found that the frequency of such specific vibrations of a DNA molecule depends on the sequence of nucleotides. Using the developed mathematical model describing the rotational motion of the nitrogenous bases around the sugar–phosphate chain, it is possible to calculate the frequency and amplitude of the oscillations of an individual DNA area. Such calculations can find application in the field of molecular nanotechnology.

Catalytic amplification by transition-state molecular switches for direct and sensitive detection of SARS-CoV-2

Despite the importance of nucleic acid testing in managing the COVID-19 pandemic, current detection approaches remain limited due to their high complexity and extensive processing. Here, we describe a molecular nanotechnology that enables direct and sensitive detection of viral RNA targets in native clinical samples. The technology, termed catalytic amplification by transition-state molecular switch (CATCH), leverages DNA-enzyme hybrid complexes to form a molecular switch. By ratiometric tuning of its constituents, the multicomponent molecular switch is prepared in a hyperresponsive state—the transition state—that can be readily activated upon the binding of sparse RNA targets to turn on substantial enzymatic activity. CATCH thus achieves superior performance (~8 RNA copies/μl), direct fluorescence detection that bypasses all steps of PCR (<1 hour at room temperature), and versatile implementation (high-throughput 96-well format and portable microfluidic assay). When applied for clinical COVID-19 diagnostics, CATCH demonstrated direct and accurate detection in minimally processed patient swab samples.

The Process of Evolution, Human Enhancement Technology, and Cyborgs

The human body is a remarkable example of the process of evolution which ultimately created a sentient being with cognitive, motor, and information-processing abilities. The body can also be thought of as an amazing feat of engineering, and specifically as an example of molecular nanotechnology, positioning trillions of cells throughout the body, and creating the billions of unique individuals that have existed since the beginning of humanity. On the other hand, from an engineering perspective, there are numerous limitations associated with the human body and the process of evolution to effect changes in the body is exceedingly slow. For example, our skeletal structure is only so strong, our body is subject to disease, and we are programmed by our DNA to age. Further, it took millions of years for Homo sapiens to evolve and hundreds of thousands of years for hominids to invent the most basic technology. To allow humans to go beyond the capabilities that evolution provided Homo sapiens, current research is leading to technologies that could significantly enhance the cognitive and motor abilities of humans and eventually create the conditions in which humans and technology could merge to form a cybernetic being. Much of this technology is being developed from three fronts: due to medical necessity, an interest within the military to create a cyborg soldier, and the desire among some people to self-enhance their body with technology. This article discusses the processes of biological evolution which led to the current anatomical, physiological, and cognitive capabilities of humans and concludes with a discussion of emerging technologies which are directed primarily at enhancing the cognitive functions performed by the brain. This article also discusses a timeframe in which the body will become increasingly equipped with technology directly controlled by the brain, then as a major paradigm shift in human evolution, humans will merge with the technology itself.

FUSOGENIC LIPOSOME FOR THE TREATMENT OF FUNGAL MENINGITIS: AN OVERVIEW

Fungal meningitis is an infection which is caused by fungus which spreads through the blood to the spinal cord. People with weakened immunity get this disease easily like persons with AIDs, etc. To make sure the disease is fungal meningitis, a sample is taken from the cerebrospinal fluid and it is sent to the laboratory. Usually, fungal meningitis is not mediated from person to person, but it is caused when a fungi are inhaled from the surrounding and spread into the blood to the central nervous system. Normally medications such as vaccines, IV, and oral suspensions are given to the people for curing fungal meningitis. Commonly used drugs are Amphotericin B and fluconazole oral suspension. Amphotericin B is an antifungal, antiprotozoal, and hydrophobic drug. However, these drugs cannot give a directly as medication therapy for the patients, because it offers toxic effect and side effects, absorption rate is slower, and crossing the blood–brain barrier (BBB) is getting difficult. Adverse effects can be minimized with the application of nanotechnology. Therefore, in human medical services, the availability of molecular nanotechnology will provide rapid progress. Nanoparticle (NP) systems help to improve the solubility of poorly water-soluble drugs which has been explained using Noyes–Whitney equations. Nanoparticles offers several advantages as a drug delivery system, such as better drug bioavailability, reduction of dosing frequency enables them for the betterment of diseases, can cross the BBB, and it is very cost-effective. Types of NP include polymeric NP, carbon nanotubes, metallic structures, nanocrystals, and fusogenic liposomes. Fusogenic liposomes are a peculiar class of phospholipid vesicles. The fusogenic liposomes can deliver encapsulated NP into the targeted sites and also can cross the BBB. On comparing with cationic liposomes, fusogenic liposomes are more effective as well as rapid in the drug delivery.

Imaging proteins at the single-molecule level

Imaging single proteins has been a long-standing ambition for advancing various fields in natural science, as for instance structural biology, biophysics, and molecular nanotechnology. In particular, revealing the distinct conformations of an individual protein is of utmost importance. Here, we show the imaging of individual proteins and protein complexes by low-energy electron holography. Samples of individual proteins and protein complexes on ultraclean freestanding graphene were prepared by soft-landing electrospray ion beam deposition, which allows chemical- and conformational-specific selection and gentle deposition. Low-energy electrons do not induce radiation damage, which enables acquiring subnanometer resolution images of individual proteins (cytochrome C and BSA) as well as of protein complexes (hemoglobin), which are not the result of an averaging process.

What are proteins teaching us on fundamental strategies for molecular nanotechnology?

Besides the fundamental competition between the top-down and bottom-up approaches in nanotechnology, there are some basic aspects for organizing structures and functions at the molecular level. The recent challenges to the development of nanotechnology are marked by a group of general requirements: selection of suited building units, overcoming the restrictions of planar technology, shrinking of nanofabrication facilities, sustainable production and management of life cycles, organization of autonomy and communication at the nano-level, and the optimization of power consumption and energy management. Looking at the natural principles in the construction, synthesis, and function of proteins helps in understanding the principal differences between the currently applied technologies and the characteristics of biomolecular mechanisms in cells. This view allows formulating seven basic rules to meet the general requirements for future developments in molecular nanotechnology.